The updating of an existing ultrasonic exposure facility is accomplished by obtaining particular electronic instruments. The original facility was designed and fabricated approximately 20 years ago and is now in need of refurbishing in order to assure that accurate and reliable usage continues. The instrumentation is essential for the exposure of animal systems to study the mechanisms of interaction, immunological response, dosimetry, and for the measuring of ultrasonic propagation properties of biological media. Updating will further make available the capability of greatly expanding the scope of the work, undertaken by the investigators dealing with different ultrasonic topics, by allowing for short pulse irradiations to be carried out, and thereby opening the research armamentari to the temporal domain of diagnostic ultrasound while providing for substantial wave amplitudes needed for interactive studies.